[Biologic characteristics of eight Podoviridae Stx2-converting phage].
OBJECTIVE
We studied biologic characteristics of Stx2-converting phage induced from Escherichia coli O157 by mitomycin C.


METHODS
Eight Stx2-converting phages were isolated from E. coli O157 and identified by PCR. The phage particles were purified and phage DNA was extracted. Random priming digoxin (DIG)-labeled stx2-specific gene probe was prepared for Southern blot. The morphology of these phages were studied by electron microscopy. Protein profiles were analyzed by Sodium Dodecyl Sulphate PolyAcrylamide Gel Electrophoresis (SDS-PAGE). Restriction fragment length polymorphism (RFLP) was used to confirm the size, type, and polymorphism of the purified phage genome.


RESULTS
These 8 phages were confirmed Stx2-converting phage and DIG-labeled probe was highly specific. All phages had a regular hexagonal head and a short tail, belonging to Podoviridae phage families. The Stx2 phages had genome sizes in the range of 48 to 65.3kb, consisting of double-stranded DNA. The restriction fragment length polymorphism of these phages showed different groups, although the SDS-PAGE protein profiles of these phages were similar.


CONCLUSIONS
These 8 Stx2-converting phages with similar morphology belonged to Podoviridae phage families. The protein profiles were highly identical. We could differentiate these Stx2-converting phages according to their restriction fragment length polymorphism patterns.
Xia
Luming
L
Shanghai Key Laboratory of Veterinary Biotechnology, School of Agriculture and Biology, Shanghai Jiaotong University, Shanghai 201101, China. xialuming@tom.com
Su
Liangke
L
Sun
Jianhe
J
Yan
Yaxian
Y
D000818:Animals; D015139:Blotting, Southern; D004279:DNA, Viral / Q000235:genetics; D004591:Electrophoresis, Polyacrylamide Gel; D004927:Escherichia coli Infections / Q000175:diagnosis / Q000517:prevention & control; D019453:Escherichia coli O157 / Q000187:drug effects / Q000821:virology*; D016679:Genome, Viral; D046529:Microscopy, Electron, Transmission; D016685:Mitomycin / Q000494:pharmacology; D017902:Podoviridae / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure; D012150:Polymorphism, Restriction Fragment Length; D022641:Shiga Toxin 2 / Q000378:metabolism*
D004279:DNA, Viral; D022641:Shiga Toxin 2; D016685:Mitomycin